Process for the production of aminomalonic acid dinitrile as an aminomalonic acid dinitriltosylate precipitate or as an acetylaminomalodinitrile precipitate

Abstract

Process for the production of aminomalonic acid dinitrile from a malonic acid dinitrile compound, such as oximinomalonic acid dinitrile or phenylazomalonic acid dinitrile. The reaction is carried out at an elevated hydrogen pressure in the presence of Raney catalysts and a solvent. When tetrahydrofurane is used as a solvent, the reaction product is precipitated with p-toluene sulfonic acid. When acetic anhydride is used as solvent, the reaction product is precipitated as acetyl aminomalonic acid dinitrile.

We claim: 
     
       1. A process for the production of aminomalonic acid dinitrile as an aminomalonic acid dinitriltosylate precipitate or as an acetylaminomalodinitrile precipitate comprising converting a malonic acid dinitrile reactant selected from the group consisting of oximinomalonic acid dinitrile and phenylazomalonic acid dinitrile to aminomalonic acid dinitrile by reducing the malonic acid dinitrile reactant with hydrogen at a hydrogen pressure of about 4 to 6 atmospheres and at temperatures of about 10° to 80° C. in the presence of a Raney nickel catalyst and a solvent selected from the group consisting of tetrahydrofurane and acetic anhydride, and precipitating and isolating the resulting aminomalonic acid dinitrile as a precipitate selected from the group consisting of aminomalonic acid dinitriltosylate and acetylaminomalodinitrile, said aminomalonic acid dinitriltosylate being precipitated by treating the resulting aminomalonic dinitrile with p-toluenesulfonic acid. 
     
     
       2. A process as claimed in claim 1 wherein said solvent is tetrahydrofurane and said resulting aminomalonic acid dinitrile is precipitated by treatment with p-toluene sulfonic acid and the precipitate is isolated from the reaction mixture. 
     
     
       3. A process as claimed in claim 1 wherein said solvent is acetic anhydride and said resulting aminomalonic acid dinitrile is precipitated and isolated as acetyl aminomalonic acid dinitrile. 
     
     
       4. A process as claimed in claim 2 wherein said treatment with toluene sulfonic acid comprises adding the p-toluene sulfonic acid to the reaction mixture in two fractions, the first fraction containing 0.02 mole to 0.03 mole of p-toluene sulfonic acid per 0.1 mole of malonic acid dinitrile reactant, the second fraction containing 0.03 mole to 0.1 mole of p-toluene sulfonic acid per 0.1 mole of malonic acid dinitrile reactant. 
     
     
       5. A process as claimed in claim 1 wherein said malonic acid dinitrile reactant is oximinomalonic acid dinitrile. 
     
     
       6. The process as claimed in claim 1 wherein said malonic acid dinitrile reactant is phenylazomalonic acid dinitrile. 
     
     
       7. The process as claimed in claim 1, 5, or 6 wherein said Raney nickel catalyst consists essentially of Ni, Fe, Cu and/or Co. 
     
     
       8. The process as claimed in claim 7 wherein the Raney catalyst is used in an amount of 60 to 80 grams per mole of malonic acid dinitrile reactant. 
     
     
       9. a process as claimed in claim 3 wherein said Raney nickel catalyst consists essentially of Ni, Fe, Cu and/or Co and is used in an amount of 60 to 80 grams per mole of malonic acid dinitrile reactant. 
     
     
       10. A process as claimed in claim 4 wherein said Raney nickel catalyst consists essentially of Ni, Fe, Cu and/or Co and is used in an amount of 60 to 80 grams per mole of malonic acid dinitrile reactant. 
     
     
       11. A process as claimed in claim 1 wherein said reduction is conducted within a time of 1 to 10 hours.